Infants and other incontinent individuals wear disposable absorbent articles such as diapers to receive and contain urine and other body exudates. Absorbent articles function both to contain the discharged materials and to isolate these materials from the body of the wearer and from the wearer's garments and bed clothing. Disposable absorbent articles having many different basic designs are known to the art. It is also known that the exterior of disposable diapers can be covered with a flexible, fluid and vapor impervious sheet to prevent any absorbed fluid from passing through the diaper and soiling adjacent articles such as clothing, bedding and the like. These outer covers, generally referred to as backsheets, are often constructed from fluid impervious films such as polyethylene. Although such backsheets do prevent fluid from passing through the diaper, they also can make the diaper feel hot and uncomfortable to wear because of their impermeability to air and/or moisture.
Backsheets which are pervious to vapor are generally known as breathable backsheets and have been described in the art. In general, these backsheets are intended to allow the passage of vapor through them while retarding, at least to a degree, the passage of fluid. For example, U.S. Pat. No. 3,156,242 issued to Crowe, Jr. on Nov. 10, 1964 teaches the use of a microporous film as a breathable backsheet. U.S. Pat. No. 3,881,489, issued to Hartwell on May 6, 1975, teaches a breathable backsheet comprising in combination two layers, the first of which is a low void volume perforated thermoplastic film and the second of which is a porous high void volume hydrophobic tissue. U.S. Pat. No. 3,989,867 issued to Sisson on Nov. 2, 1976 teaches a breathable backsheet provided with tapered hollowed bosses which prevent the passage of fluids while allowing vapors to pass readily therethrough.
While these backsheets do provide improvements over the commonly practiced impermeable backsheets of the prior art, they have been found to not be sufficiently fluid impervious when subjected to normal usage conditions. For example, when used as a backsheet on a disposable diaper, the backsheets may permit the transmission of urine upon impact from an infant sitting down. This ability of a fluid to be forced through such materials results in the unwanted transmission of urine waste through the diaper backsheet.
Therefore, it is an object of the present invention to provide a disposable absorbent article backsheet having good containment characteristics while being breathable to ensure comfort for the wearer.
It is yet another object of this invention to provide a disposable absorbent article having a breathable backsheet having good containment characteristics when subjected to normal usage conditions.
These and other objects of the present invention will be more readily apparent when considered in reference to the following description and when taken in conjunction with the accompanying drawings.